For the desktop app, I have "open new tab next to current tab" and "when opening a link in a new tab, make it active" both enabled with "show nested vertical tabs" also enabled. When I'm working on something and need to open a new tab to search for something new or need to click on a link, it creates this mini tree that's great and I love it. It keeps my tabs organized in a natural way that's easy to navigate and later clean up.
At the same time, when I want to open a new tab for a new topic, this behavior is not desired. I'd like to create a new top level tab so I can start a new chain of thought. Right now, I have to create a tab and then drag it to a specific place for the tab bar to figure out I want it to be top level and not nested which is sometimes quite difficult.
I'd like it if there were a keyboard shortcut like Command+Shift+T or something else (no preference for what the shortcut is) that was a "New top level tab".
The way I would use it is to quickly create a new top level tab for organization. It would just make the process I described above faster. I still think the default new tab button should create the nested tab though.
I'm not familiar with how other browsers implement this. It's my first time utilizing tab groups or nested tabs in a browser.